\begin{tikzpicture}
            %------------------------------------------------------------------------------------
            {\small
% 同一个父亲的孩子锚定点间的距离 层间距离
        \begin{scope}[sibling distance=10pt, level distance=38pt]
        \Tree[.\node(a1){Sp};
             	[.\node(b1){Sbj}; [.\node(c1){r};]]
             	[.\node(b2){Prd};
                        [.\node(c2){Pp};[.\node(d1){p};]
                                        [.\node(d2){Np};
                                            [.\node(e1){n};][.\node(e2){c};][.\node(e3){n};]]]
                        [.\node(c3){Vp};[.\node(d3){u};][.\node(d4){v};]]]
             	[.\node(b3){Obj};
             	    [.\node(c4){Np};[.\node(d5){a};][.\node(d6){n};]]
             	]
             ]
        \end{scope}
        }

            %------------------------------------------------------------------------------------
            \end{tikzpicture}